require(httr)

cookies = c(
  'X-BackEndCookie' = 'S-1-5-21-1234556-56678-12345-2345=alphanumericstring12345/anotheralphanumericstring12345/scsiAdf/P',
  'ClientId' = 'LoremIupsum',
  'PrivateComputer' = 'true',
  'PBack' = '0',
  'cadata' = 'bx88rrCBehITlBWSozO2l2hlFGu//JjT1/k6dewX5shV32jANUZSMU6GR+M25B6YpBODEgXzxfIHDnvxNC6SJoaE/d8RWX3uDnbkd+m91jNhMXNSYIRYTJHVFdPG06AE',
  'cadataTTL' = 'NfDhBViTJMUdC+ir+6BYvg==',
  'cadataKey' = 'qUY+OLTD9V14CFK6/CUPyrJWMxl1FFqZFjB8/qcS0/q55eqGvP9bWvX+XuSYVv3hIGAn9QNPhIDK6NP9LwCBdu25f2BUFDUWJruGO8MW02izSWzRUnni00xWQq3Y3nNKvpvO+OIR641BPHVZ0+lzCw2Wt8uzEnryCWAjlleozF/XWjpTN4/AaTmcIjEZUDN+fo4494rD0mADtEHv2gmd5mhLe+iyii/L9nAB3UuiJomwbRbKgy22Tj8cyavmLC4ZaViqW9E102NOLU4FYLgdZVET+mbdg==',
  'cadataIV' = 'bTM88YL1zmz7FsBEB0y3nI2SrdSTy+KLxCpx2FRfIZYFo2spN1IHQMSCT76OXrg79sVPhyqXk+N9rOj6M9KsQl4KqMNVBcoXgp24POpgoTwd4FBmKtAYbd9SDErna3jrMO168ML9PDG18K3CnBf6YG1tsIs0gXOEP9LzHVmUPF7KCKqUFiOiZGWuwmPhl85eo77BbEpVN2JkPnzuQWn6tC0cY4f2cJDlr3Z23SrAUVwwXmgRg2DXfOF5MIEkpwYiiI6sABCD9rsSnE6zTXlvZg33hjiD/ywUV1ZWjI2M/4zBixa4s150+dOnMmvtEFs/nOMnvMJui4PEDlTA==',
  'cadataSig' = 'WL3hB+av7sO3bzjL+Efe5b4exnvQxSInH3U5jDvfnPcttSp0XUF3y/NB573C0CTBYuOH/40smFssXlrKhT9tG2ITivdSIIamOmarmC8XwFOv9qQIFMHofcO/jjRDMqF0qRk7WBAC2FgBQrf2Tvq7wk5IX/JHn6zhlgKALAAqH9L9JNC244etnjj9YNaMDYEHV2M2jVTu3FsELqw1rSSqp0hEBlh+aFBvYCBg5hS1mVI76ZCHZVa0OUejiH2yiZyJIKHUI+Sv0rpU3iiQNtIFmGEdwhoo/rga4s4Dc2UsJLQ8c0yGlZgflYs+7Q5gPr74/mTUin60ej/w3M0roUl3FQ==',
  'UC' = 'd8be544621964f3c9865b3ee872fd432',
  'AppcacheVer' = '15.0.1236.3:en-usbase',
  'X-OWA-CANARY' = 'VOXQP6xtGkiNnv7E4rFt8TrmclqVFtQI4IJqZflrR7Wz9AMPkMsFoyAlquw1YGsTUxIkVouAcvk.'
)

headers = c(
  `Origin` = 'https://nih.mail.edu.fr',
  `Accept-Encoding` = 'gzip, deflate, br',
  `X-EWS-TargetVersion` = '2.5',
  `Accept-Language` = 'en-US,en;q=0.8',
  `User-Agent` = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36',
  `Action` = 'CreateItem',
  `X-Requested-With` = 'XMLHttpRequest',
  `Connection` = 'keep-alive',
  `X-OWA-CANARY` = 'VOXQP6xtGkiNnv7E4rFt8TrmclqVFtQI4IJqZflrR7Wz9AMPkMsFoyAlquw1YGsTUxIkVouAcvk.',
  `X-OWA-ActionName` = 'CreateMessageForComposeSend',
  `X-OWA-ActionId` = '-37',
  `X-OWA-ServiceUnavailableOnTransientError` = 'true',
  `Content-Type` = 'application/json; charset=UTF-8',
  `Accept` = '*/*',
  `Referer` = 'https://localhost/api/',
  `X-OWA-ClientBuildVersion` = '15.0.1236.3',
  `X-OWA-CorrelationId` = '2f11f8fb-f6c6-43a5-881d-8a1b242a4e70_148023102251337',
  `DNT` = '1',
  `X-OWA-ClientBegin` = '2016-11-27T07:17:02.513',
  `X-OWA-Attempt` = '1'
)

params = list(
  `action` = 'CreateItem',
  `ID` = '-37',
  `AC` = '1'
)

data = '{"__type":"CreateItemJsonRequest:#Exchange","Header":{"__type":"JsonRequestHeaders:#Exchange","RequestServerVersion":"Exchange2013","TimeZoneContext":{"__type":"TimeZoneContext:#Exchange","TimeZoneDefinition":{"__type":"TimeZoneDefinitionType:#Exchange","Id":"France Standard Time"}}},"Body":{"__type":"CreateItemRequest:#Exchange","Items":[{"__type":"Message:#Exchange","Subject":"API","Body":{"__type":"BodyContentType:#Exchange","BodyType":"HTML","Value":"<html><head><meta http-equiv=\\"Content-Type\\" content=\\"text/html; charset=UTF-8\\"><style type=\\"text/css\\" style=\\"display:none\\"><!-- p { margin-top: 0px; margin-bottom: 0px; }--></style></head><body dir=\\"ltr\\" style=\\"font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;\\"><p>API Test for NickC<br></p></body></html>"},"Importance":"Normal","From":null,"ToRecipients":[{"Name":"George LUCAS","EmailAddress":"George.LUCAS@nih.mail.edu.fr","RoutingType":"SMTP","MailboxType":"Mailbox","OriginalDisplayName":"George.LUCAS@nih.mail.edu.fr","SipUri":" "}],"CcRecipients":[],"BccRecipients":[],"Sensitivity":"Normal","IsDeliveryReceiptRequested":false,"IsReadReceiptRequested":false}],"ClientSupportsIrm":true,"OutboundCharset":"AutoDetect","MessageDisposition":"SendAndSaveCopy","ComposeOperation":"newMail"}}'

res <- httr::POST(url = 'https://localhost/api/service.svc', httr::add_headers(.headers=headers), query = params, httr::set_cookies(.cookies = cookies), body = data)

#NB. Original query string below. It seems impossible to parse and
#reproduce query strings 100% accurately so the one below is given
#in case the reproduced version is not "correct".
# res <- httr::POST(url = 'https://localhost/api/service.svc?action=CreateItem&ID=-37&AC=1', httr::add_headers(.headers=headers), httr::set_cookies(.cookies = cookies), body = data)
